Gripping device for rotaries



Sept 16, 1924. 1,508,590

B. BOYKIN, JR

GRIPPING DEVICE FOR ROTARIES Filed June 5` 1922 Marktnet,

meer sepa. ie, 1924.

T E s lBunn Bovxm, JR.,

OFFICE.

or' BEAUMONT, TEXAS.

GBIPPING- DEVICE FOR ROTAJRIES..

Application filed June 5,

which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to l@ make and use the same.

My invention relates to a means for gripping the drive stem in rotary drilling operations.

Tt is common in drilling deep wells for 15 oil, gas, sulfur and the like, to employ the rotary system of drilling, wherein the drill stem or pipe is rotated by means of a rotary table through which the drill stem projects. The upper .end of the drill stem is usually made up of a special length of heavy pipe with Hattened or grooved sides whereby a gripping device upon the rotary table may betterhold the same in rotating. This section of pipe is variously called the drive stem, grief stem or kelly joint.` There are var1ous gripping devices employed to hold this drive stem against rotation relative to the rotary tablev so that the rotation of the table will rotate said drive stem.

Most of them have rollers arranged to t about the drive stem and hold it firmly for operation but allowing the rolling of the pipe on the said rollers. An improved eX- ample of this type of gripping device is shown in my co-pending application Serial No. 561,178, filed May 15th, 1922., patented March 27, 1923,- Numbered 1,449,647, of which this invention is an improvement. The objection to the roller gripping device is that the rollers have buta short line of contact with the drive stem and hence are liable to wear rapidly. It will be seen that the drive stem is tangent to the rollerl and the point where the driving grip occurs is somewhat unstable, thus allowing excessive vibration of the parts.

It is an object of this invention to obtain a roller wherein the surface of Contact with the drive stem will be elongated so as to more firmly seize the pipe and prevent wear in use.

1922. Serial No. 566,155.

Another object is to provide a gripping device which may be detachably connected yto rotaries and wherein a plurality of gripping surfaces are provided, one of which may be substituted for another where wear occurs.

Another object is to provide means for adjusting the gripping device so as to provide for maintaining an ettcient gripping contact with the pipe at all times.

Further objects and advantages will be apparent from the more detailed description which follows Referring to the drawing, Fig. l is a top plan View of my improved gripping device; Fig. 2 is a side elevation thereof; Figs. 3 and 4 are top plan views illustrating a different embodiment of the gripping block; and Fig. 5 is a side elevation of one of the plates or washers employed with the embodiment shown in Fig. 4. 'Like numerals are applied to like parts throughout the several views. l

It will be noted that the mounting for the gripping blocks shown in the drawing is not materially diEerent from the mounting disclosed in my co-pending application No. 561,l78 previously referred to. There is a lower tapered bushing l adapted to fit within a tapered seat in the rotary table. At the upper end of this tapered portion is a squared head 2 adapted to lit within a squared recess in the said rotary table. Above the head 2 is an oblong plate 3 fitting over the upper surface of the rotary table and serving as a base or mounting for the gripping blocks. v Y

The bushing l and head 2 and the plate 3, are all provided with a. central opening therethru which is circular and somewhat largerthan is the pipe or drillstem which is adapted to pass therethrough. i At each end of the plate 3 are opposite pairs of supporting posts 4. These supports, as

vshown in Figs. 1 and 2, are spaced apart a fit within slots 7 in each of the posts 4. These slots are wider than is the squared end of the shaft 6 so that a series of adjusting plates or washers 8 may be fitted at one side thereof, and a locking block 9 maybe placed above the shaft to hold the same firmly in position. This block is itself locked in place by means of a cross pin 10 passing through the sides of the support 4 and through the lockingblock 9, and held there by means of cotter pins 11.

The .gripping blocks 5 are preferably square when viewed transversely as shown in Fig. 2. The gripping periphery of the block is shaped to fit against the drive stem 12. When the drive stem is square as shown in Figs. 1 and 2 the block is preferably formed with V-shaped grooves in each of the four sides thereof. Thus when the clamping blocks are adjusted toward each other so as to lit about the pipe as "shown in Fig. 1 there will be a bearing contact with the drive stem which will extend nearly the full Width of the clamping blocks. The

stem 12 of different shape.

blocks will therefore be better adapted to rotate the drive stem than will be the case where the roller is round as previously described. When wear occurs on the blocks the shafts 6 may be adjusted so as to throw the clamping blocks 5 toward the drive stem by shifting some of the plates or washers 8 from the inner side of the shaft 6 to the opposite side. Further, when it is found that the wear has become excessive, the clamping blocks 5 may be rotated through 90 degrees so as to present another clamping face to the drive stem. This rotation may be accomplished be removing the lockin pin 10 and the block 9 and raising the sha t 6 upwardly out of the slot until enough space is provided to rotate the clamping block 5 upon the shaft. When the new face is presented to the drive stem, the shaft may be lowered again into its bearing and locked into position as described above. This may be repeated when necessary until the four sides of the block have become wornI and thus make it necessary to provide a new gripping block. c

In Fig. 3 I have illustrated a dierent shaped gripping surface upon the block. This different shape is used to accommodate the clamping ofthe device to a drive The pipe is iiuted lor grooved longitudinally at 13 to receive the sides of the gripping block 4" These blocks are square when as shown. vlewed from the side and are mounted` 1n the same manner as are the'blocks shown in;

is cross-shaped in transverse section.

this modification however, I have made the blocks 4 further adjustable by the use, between the two end blocks 14, of a series of intermediate thinner plates of smaller dimension, l5. This block may be adjusted to take up wear by removing one of the plates 15 when necessary so as to bring the side' plates 14 closer together. It is also possi-ble to rotate these blocks upon their shaft in the same manner as described lin connection with' the modification shown in Figs. 1 and 2. Furthermore, each of the side blocks 14 may be removed from the shaft and reversed with the outer face inwardly when desired, so as to present a new gripping surface to the drive stem 12".

lWhen the plates or washers 15 are removed surface of contact presentedl against theV drive stem, the wear will not be excessive. Furthermore the surfaces, when once worn, may be moved out of contact with the pipe and a new driving surface cused to grip the drive stem. The gripping blocks will be spaced from the pipe a suiicient distance to allow a free vertical sliding movement of the pipe relative to the jaws, as is usual,

with this type of ipping means. The use of the squared bloc will also hold the drive stem more firmly because the blocks will rest upon the plate 3 of the supporting bushing and thereby prevent the usual amount of vibration which occurs with the ordinary rollers now employed in gripping the p ipe. Having thus described my inventlon,

what I claim is new and desire to protect by Letters Patent is:

1. A gripping devlce for rotary drive stems comprising a supporting base, two parallel shafts mounted .in spaced relation on said base, and gripping blocks mounted on said shafts, each of vsaid blocks-having a polygonal periphery, one side of whlch contacts with said base the sides, thereof being grooved 4to fit a drive stem.

2. A gripping device f or rotary drive stems comprising a supporting base, bearing shafts supported in spaced relatlon thereon, a clamping block on each of said shafts, said blocks being polygonal and grooved peripherally to clamp the drive stem, one side of each of said blocks contactmg with the base to prevent relative movement of said blocks during use.

s 3.14v gripping device for rotary. drive 'stems comprising .a supporting base, opone of the faces of each said block adapted posite pairs of beerin posts on said base, to contact with the said base to prevent roshefts mounted in ea@ said pair of posts, tation thereof in use. e 10 a drive stem gripping device on each said In testimony whereof, I hereunto aiix my 5 sheft comprising squared blocks, havinsg 'signature this the 1st day of June, 1922.

polygonal grooves formed in each periphemi face thereof to tit the said drive stem, BURLL BUYKIN, JR. 

